You might want to consider more than just washers under the track. With the original Pearson issue track, I have had both pulled through the deck,taking the deck with them. Today I have a stainless plate, about an inch wide, extending beyond the length of the track.

The principal problem occurs when the car is at either end of the track. The strain can pop the first through hole, then the second - right down the line.

My tracks are on the deck, so the problem may be worse than on the toe rail, but it is still something to think about. Particularly, with the minimal width of the toe rail, the washers can't be that big, I would imagine.